MyBatis框架基础模板+举例

搭建 MyBatis 开发环境 

下载 mybatis-3.2.2.jar 包并导入工程 

编写 MyBatis 核心配置文件(configuration.xml)

 创建实体类-POJO

 DAO 层-SQL 映射文件(mapper.xml)

 创建测试类

 读取核心配置文件 mybatis-config.xml

 创建 SqlSessionFactory 对象，读取配置文件

 创建 SqlSession 对象

 调用 mapper 文件进行数据操作

1，dao包下仅写接口即可

2，database.properties文件

driver = com.mysql.cj.jdbc.Driver
url = jdbc:mysql://localhost:3306/smbms?useSSL=false&serverTimezone=UTC
username = root
password = root

3，mybatis-config.xml文件

注:若pojo表内名称和数据表内不相同则需要手动添加映射

4，mapper包下新建xml文件，主要写sql语句，xml文件名最好和dao包下的接口名相同

    
        select * from `smbms_user`;
    

    
 
        select * from `smbms_user` where `userCode` = #{userCode};
    

注:若pojo表内名称和数据表内不相同则需要手动添加映射

测试类

import dao.UserMapper;
import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
import pojo.User;

import java.io.IOException;
import java.io.Reader;
import java.util.List;

public class test {
    public static void main(String[] args) throws IOException {
        //1,读取mybatis-config.xml
        Reader reader = Resources.getResourceAsReader("mybatis-config.xml");
        //2,创建SQLSession对象
        SqlSessionFactory factory = new SqlSessionFactoryBuilder().build(reader);
        SqlSession session = factory.openSession();
        //3,使用session来访问接口方法

        //方法一：直接运行sql语句
        List list = session.selectList("getAll");
        for (User user:list) {
            System.out.println(user.getGender()+"t"+user.getUserName());
        }
        User user = session.selectOne("getByUserCode","admin");
        System.out.println(user.getGender()+"t"+user.getUserName());

        System.out.println("**************************************");

        //方法二:基于Mapper接口(只要记住一个getMapper)
        //UserMapper是dao下的接口方法
        List list1 = session.getMapper(UserMapper.class).getAll();
        User user1 = session.getMapper(UserMapper.class).getByUserCode("liming");
        for (User users:list) {
            System.out.println(users.getGender()+"t"+users.getUserName());
        }
        System.out.println(user1.getGender()+"t"+user1.getUserName());
    }
}